1. Postdoctoral Fellow, Dept. of Civil and Environmental Engineering, Univ. of Alberta, 9105 116 ST, 5-080 NREF, Edmonton, AB, Canada T6G 2W2.
2. Professor, Dept. of Civil and Environmental Engineering, Univ. of Alberta, 9105 116 ST, 5-080 NREF, Edmonton, AB, Canada T6G 2W2 (corresponding author).